A new peptide/protein sequencer and two accessory instruments (a microbore HPLC and a capillary electrophoresis system) are requested for the Wistar Protein Microchemistry Core Facility. The requested sequencer will replace a 12-year-old ABI model 470A gas phase sequencer. Replacement of this sequencer is critical for two reasons: first, the acquisition of a modern multi-cartridge sequencer will moderately expand our sequencing capacity through the multi-cartridge feature and decreased "down time", and second, the existing 12-year-old instrument has reached the end of its useful lifetime with a steadily increasing repair frequency. Due to the steadily declining reliability of this older sequencer, analysis of critical samples has become unacceptably risky, which severely limits its usefulness. In addition, Applied Biosystems has announced that support for this instrument will be discontinued next year. The microbore HPLC and capillary electrophoresis units will complement the sequencer. Both accessories will be used for micro scale peptide isolations, and the capillary electrophoresis unit will also be used to evaluate purity of selected samples prior to sequence analysis. The requested instruments would provide critical protein structural information for a major user group of 9 principal investigators, including one major user from the adjacent U. of Pennsylvania Medical School. The remainder of instrument time will be available to a minor user group consisting of 16 principal investigators. All major users and most minor users have NIH grant support. The Wistar Protein Microchemistry Laboratory is available to all investigators at the Wistar Institute and has been used by about 80% of all institute laboratories (from a total of 50) since the facility commenced operation in early 1987. The facility has also provided protein chemistry analyses and support to about 80 investigators from other research institutions since its inception. These "outside" investigators represent seven other universities/research centers in the Philadelphia area as well as additional institutions across the country. The largest concentration of outside users is from the neighboring University of Pennsylvania campus and Medical School (26 investigators), followed by the other Philadelphia area institutions. The majority of all past users of the facility are NIH funded investigators. An internal advisory committee, comprised of all major users, two minor users, and the Wistar Institute Director of Core Facilities will oversee operation and administration of the instrument. The Wistar Institute is committed to housing, maintaining and staffing the requested instrument for its useful lifetime, as verified by an accompanying letter from the Institute Director.